Some thoughtful fine tuning of Obama's tone and focus:

ABC News -

Obama said he has gotten wrapped up in negative campaigning recently, which has distracted him from his reason for running, and said he spoke with his campaign team about changing the focus.

"I noticed over the last several weeks, I told this to my team, you know we are starting to sound like other folks - starting to run the same negative stuff. And it shows you  that none of us are immune from this kind of politics. But the problem is that it doesn't help you.  Having politicians bickering back and forth doesn't help you. Having them worry about superdelegates doesn't help you."

Again, Obama repeated his new focus, not the other candidates, but he says, the American people.

"This election is not about me. It's not about Sen. Clinton. It's not about John McCain. It's about you. It's about your struggles, your hopes, your dreams."

    More than breaking with the recent negativity, more than connecting with blue collar workers, he's turned his focus solely to the populace and its needs.  This is where Obama should be to connect more broadly, to hit the wider harmonies among people. 
    This honed message also reflects a core strength of Obama's, something neither Clinton nor McCain are especially know for -- the capacity to draw in all kinds of perspectives and foster agreement.